Commercial earth observation satellites, such as Ikonos and Geoeye-1, offer imagery of ground-based targets. These satellites typically offer multispectral (MSI) imaging, which provides images at red, green, blue, and near-infrared wavelengths, and panchromatic (PAN) imaging, which provides black-and-white images formed from wavelengths that span the visible spectrum. This imagery is commonly referred to as electro-optical (EO) imagery.
In many cases, the multispectral images show registration errors with respect to one another and with respect to 3D sources such as LADAR. For instance, shadows that appear on the ground and green leaves from a tree may erroneously spill onto a roof of an adjacent building, or white vent covers on a non-white roof may not be aligned with their proper three-dimensional locations. These are but two specific examples; other registration errors are possible. These registration errors may complicate use of the multispectral images, and can introduce uncertainty in downstream applications that rely on the multispectral images to locate particular objects.
Laser Detection and Ranging (LADAR), typically obtained from aircraft that fly over the ground-based targets, can produce a three-dimensional profile of the targets. LADAR can produce a collection of points that represent the surface or surfaces of the targets, which is often referred to as a point cloud. However, because typical LADAR uses only one eye-safe wavelength, typical LADAR does not return color data from the target. In addition, LADAR 3D data is often misregistered with respect to the MSI images, due largely to uncorrelated geometric support data errors between the two sources. Manual registration of LADAR and 3D data is time consuming, and thus seldom performed accurately.